Part 1
Tally is an ugly. But soon, when she turns sixteen years old, she will turn into a pretty. The city is separated into different parts. Tally is an ugly, but her friend Perris has already turned into a pretty. She misses him, so she decides to go into New Pretty Town, where all the new pretties live. Uglies are not allowed in, but she does it anyways. When she arrives at the Garbo mansion, where the new pretties live, she caused panic at the party. After that, she escapes from the Garbo mansion and meets Shay. Shay teaches Tally how to hover board. They become friends.

Part 2
They start thinking about what being a pretty is. Shay doesn't seem to want to be a pretty. She has know about a guy named David, who takes runaways to the Smoke. The Smoke is a village and they live like the Rusties (now). Shay takes Tally to a roller coaster, and use hover boards instead of carts. The roller coaster is far away from the city and beyond the suburbs. This is farther than Tally has ever gone, and she wonders what lies ahead. A few weeks before the operation, Shay runs away to The Smoke, and left Tally some clues. On the day of her and Shay's sixteenth birthday, Tally waits from Uglyville school to be picked up to get her operation. Instead of going to the operation, she gets to go to the Specials building. The Specials are cruel pretties and nearly nobody has seen what they look like. They asked Tally to follow the clues and go to The Smoke and infiltrate it, or else she won't get her operation.

Part 3
She decides to follow the clues. This leads her to an adventure. Some of Shay's clues were hard to decipher, but Tally made it. She meets Shay and David there. She does hard-core labour, like pulling metal from the Rusty's train tracks to make a line for hover boards (they need metal to run on). She falls in love with David, even though she knew Shay liked him. She decides that she does want to live there, and throes the heart pendant (that the Specials gave to her to activate when at The Smoke) into a fire.